body{
    background: #f7f7f7;
}
.px2rem(@name, @px) {
    @{name}: @px / 75 * 1rem;
}
.txh {
    display: flex;
    display: -webkit-flex;
}
.der{
    .txh();
    .px2rem(height,100);
    justify-content: flex-start;
    align-items: center;
    background: white;
    span{
        .px2rem(font-size,36);
        .px2rem(padding-left,200);
//      padding-left: ;
    }
}
.ass{
    ul{
        .px2rem(padding-top,130);
        li{
            width: 90%;
            margin-left: 5%;
            .px2rem(height,100);
            border-bottom: 1px solid darkgray;
        }
        li:nth-child(1){
            input{
                .px2rem(height,60);
//              .px2rem(width,);
                width: 100%;
                .px2rem(margin-top,35);
                border:1px solid #f7f7f7;
                .px2rem(font-size,32);
                background: #f7f7f7;
            }
        }
      
        li:nth-child(2){
            input{
                .px2rem(height,60);
//              .px2rem(width,);
                width: 100%;
                .px2rem(margin-top,35);
                border:1px solid #f7f7f7;
                .px2rem(font-size,32);
                background: #f7f7f7;
            }
        }
        
        li:nth-child(3){
            input{
                .px2rem(height,60);
//              .px2rem(width,);
                width: 50%;
                .px2rem(margin-top,35);
                border:1px solid #f7f7f7;
                .px2rem(font-size,32);
                background: #f7f7f7;
            }
             button{
            .px2rem(border-radius,20);
//          border-bottom-left-radius: ;
.px2rem(margin-top,20);
color: white;
.px2rem(font-size,32);
.px2rem(margin-left,80);
            background: #444444;
            border: 1px solid #444444;
            .px2rem(width,134);
            .px2rem(height,70);
        }
        }
        
          
        
        
        
        
        
        
        
        li:nth-child(4){
            border-bottom: 1px solid  #f7f7f7;
            button{
                 width: 95%;
                 .px2rem(height,100);
                 background: #444444;
                 color: white;
                 .px2rem(font-size,40);
                 text-align: center;
                 .px2rem(line-height,100);
                 .px2rem(margin-top,50);
                 border: 1px solid #444444;
            }
                
        }
    }
}